I'm presently developing what should be a simple bash script that creates random wallpapers for the QTopia desktop. Instead of issuing commands to restart the desktop via qcop (or killing and starting the launcher via command line), I would like to simply refresh the background so that it reflects the newest wallpaper...

Could anyone here help me in determining the proper qcop commands (or point me in the direction of fully documented signals for the QTopia desktop) to achieve this desired effect?